The Darlington School in Rome, about 70 miles from Atlanta, opened the investigation after a former student accused a one-time teacher of sexual misconduct. The former student says the school failed to act when his mother first reported the abuse in 1988.

Darlington, where tuition and boarding run about $50,000 a year, hired a law firm to look into the former student’s allegations and other possible incidences of abuse. The school sent a letter about the investigation to about 10,000 alumni, former faculty and staff members and others late last month.

“We see this communication as an important next step in our investigation,” the school said in a statement. “If someone has relevant information to share, we want to hear from them. Ultimately, we want to know the truth.”